[Pw_forum] relaxation: mistake in finding the lowest energy structure

Dear all, I would like to study the interaction between 2 organic molecules (contains O, H, and C atoms). As the first step I relax ​ed​ the structure ​ ​(​ using ​ calculation = 'relax' in ) . ​M​ y problem is that after finishing the run, it could not find the lowest energy s ​tructure . And I

Re: [Pw_forum] how to define celldm(4) or cos(ab) for monoclinic system.

sorry but I don't really know what ubiqueb would be. i doubt it is a quantum espresso input parameter. stefano On 30/06/2016 18:34, Lori 91 wrote: Thanks a lot Stefano but in My caluclation with space group 15 must I put ubiqueb=.true.??? Thanks a lot Inviato da iPhone Il giorno 30 giu 2016,

Re: [Pw_forum] how to define celldm(4) or cos(ab) for monoclinic system.

Thanks a lot Stefano but in My caluclation with space group 15 must I put ubiqueb=.true.??? Thanks a lot Inviato da iPhone > Il giorno 30 giu 2016, alle ore 18:25, Stefano de Gironcoli > ha scritto: > > The code assumes that the non-right angle is gamma= the angle between

Re: [Pw_forum] how to define celldm(4) or cos(ab) for monoclinic system.

The code assumes that the non-right angle is gamma= the angle between a and b axes. Hence A=6.63.. B=21.09.. C=6.10.. cosab=cos(115.39..) stefano (sent from my phone) > On 30 Jun 2016, at 18:05, Lorenzo Donà wrote: > > Dear all I really hate no idea how to define

[Pw_forum] how to define celldm(4) or cos(ab) for monoclinic system.

Dear all I really hate no idea how to define cilldm(4) or cosab I have searched in pw.x mail archive and red the pw.x input documentations but really i don’t understand how to define it. I have a system with this lattice parameters: A B CALPHABETA

[Pw_forum] epsilon calculation in the case of a soft mode

Dear all, I'm studying an oxide with an optical mode frequency that is imaginary before applying a.s.r. and becomes real once a.s.r is applied. In the same input file for dynmat.x I requested computing epsilon. But it seems that epsilon is calculated based on frequencies (w2) before applying

Re: [Pw_forum] Band Offsets too large

Dear Mostafa Youssef, Thank you. I get values that are much closer to literature. Dae Kwang Jun On Thursday, 30 June 2016, Mostafa Youssef wrote: > Dear Dae Kwang Jun > > Equation (1) that you wrote is the correct one. > > And you are right bulk V_AlAs and bulk V_GaAs are

Re: [Pw_forum] Band Offsets too large

Dear Dae Kwang Jun Equation (1) that you wrote is the correct one. And you are right bulk V_AlAs and bulk V_GaAs are obtained in a similar way as in the interface but you need bulk cells. Their values can be anything , positive or negative it does not matter and in fact they are arbitrary.

Re: [Pw_forum] Band Offsets too large

Dear Mostafa Youssef, Thank you for your reply. I am not sure whether I understand what it is meant by "where EVBM_AlAs is referred to bulk V_AlAs and EVBM_GaAs is referred to bulk V_GaAs." I am assuming that the complete formula is either (1) EVBM_offset = (EVBM_AlAs - bulk V_AlAs) - (EVMB_GaAs

Re: [Pw_forum] PWneb reads coordinates of images incorrectly

The NEB code performs a linear interpolation of the "images" (routine "initial_guess", module "path_base"). This is the expected behavior if one provides only the end points. If one provides an already interpolated path, it has no effect. If however you provide a path that doesn't fall in either

Re: [Pw_forum] Band Offsets too large

Dear Dae Kwang Jun In addition for each bulk calculation one needs to calculate the bulk average electrostatic potential. Then for each compound you refer its EVBM to the electrostatic potential calculated in its bulk (not yet the interface). Only then you can use the interface

Re: [Pw_forum] Band Offsets too large

Dear Mostafa Youssef, I believe that I did that. I am not sure whether we both have the same thing on mind, however. Here is what I did. I calculated the band structures for both AlAs and GaAs using pw.x with calculation = 'bands' after the scf calculations. The VB Maxima of AlAs and GaAs occur

Re: [Pw_forum] Band Offsets too large

Dear Dae Kwang Jun, You also need 2 bulk calculations for AlAs and GaAs to get their band edges with respect to to their bulk electrostatic potentials. Then you can use the interface potential to align the band edges of the two semiconductors. It looks like you missed this step. Mostafa